:root{
  --primary:#1a73e8;--primary-dark:#1557b0;--primary-light:#e8f0fe;
  --accent:#f4b400;--accent2:#34a853;--danger:#e74c3c;
  --bg:#f0f4ff;--bg2:#fff;--text:#1a1a2e;--text2:#5f6b7a;
  --card-bg:#fff;--border:#e2e8f0;
  --shadow:0 4px 24px rgba(26,115,232,.09);
  --shadow-lg:0 12px 40px rgba(26,115,232,.16);
  --radius:16px;--radius-sm:10px;--transition:.3s ease;
  --gradient:linear-gradient(135deg,#1a73e8,#0d47a1);
}
body.dark{
  --bg:#0b0f1a;--bg2:#131929;--text:#e4ebf8;--text2:#8899b0;
  --card-bg:#1a2235;--border:#252e45;--primary-light:#1a2a4a;
  --shadow:0 4px 24px rgba(0,0,0,.4);--shadow-lg:0 12px 40px rgba(0,0,0,.5);
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:"Segoe UI",Tahoma,Arial,sans-serif;background:var(--bg);color:var(--text);transition:background .3s,color .3s;line-height:1.6}
a{text-decoration:none;color:inherit}ul{list-style:none}
img{max-width:100%}

/* ── SCROLLBAR ── */
::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:var(--primary);border-radius:3px}

/* ── NAVBAR ── */
.navbar{display:flex;align-items:center;justify-content:space-between;padding:0 2.5rem;height:66px;background:var(--bg2);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:1000;box-shadow:var(--shadow)}
.nav-logo{display:flex;align-items:center;gap:.6rem;font-size:1.2rem;font-weight:800;color:var(--primary)}
.nav-logo i{font-size:1.4rem}
.nav-links{display:flex;flex-wrap:wrap;gap:.15rem;align-items:center}
.nav-links a{display:flex;align-items:center;gap:.3rem;font-size:.8rem;color:var(--text2);font-weight:600;padding:.42rem .72rem;border-radius:8px;transition:var(--transition);white-space:nowrap}
.nav-links a:hover,.nav-links a.active{background:var(--primary);color:#fff;font-weight:700}
.nav-actions{display:flex;align-items:center;gap:.7rem}
.dark-btn{background:none;border:1.5px solid var(--border);border-radius:9px;padding:.4rem .75rem;cursor:pointer;color:var(--text);font-size:1rem;transition:var(--transition)}
.dark-btn:hover{background:var(--primary);color:#fff;border-color:var(--primary)}
.nav-toggle{display:none;background:none;border:none;padding:.45rem .6rem;cursor:pointer;color:var(--text);font-size:1.3rem;border-radius:8px;transition:var(--transition);order:3}


/* ── HERO ── */
.hero{display:flex;align-items:center;justify-content:space-between;padding:5rem 4rem;gap:3rem;background:var(--bg2);overflow:hidden;position:relative}
.hero::before{content:"";position:absolute;top:-40%;right:-10%;width:600px;height:600px;background:radial-gradient(circle,rgba(26,115,232,.08),transparent 70%);pointer-events:none}
body.dark .hero::before{background:radial-gradient(circle,rgba(26,115,232,.12),transparent 70%)}
.hero-content{max-width:580px;position:relative;z-index:1}
.hero-badge{display:inline-flex;align-items:center;gap:.5rem;background:var(--primary-light);color:var(--primary);padding:.35rem 1rem;border-radius:20px;font-size:.85rem;font-weight:700;margin-bottom:1.2rem}
.hero-content h1{font-size:2.9rem;line-height:1.3;margin-bottom:1.2rem;font-weight:800}
.accent{color:var(--primary)}.accent2{color:var(--accent2)}
.hero-content p{font-size:1.1rem;color:var(--text2);margin-bottom:2rem;line-height:1.75}
.hero-btns{display:flex;gap:1rem;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:.5rem;padding:.8rem 1.8rem;border-radius:11px;font-size:.97rem;font-weight:700;transition:var(--transition);border:none;cursor:pointer;font-family:inherit}
.btn-primary{background:var(--gradient);color:#fff;box-shadow:0 4px 14px rgba(26,115,232,.35)}
.btn-primary:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(26,115,232,.45)}
.btn-outline{border:2px solid var(--primary);color:var(--primary);background:transparent}
.btn-outline:hover{background:var(--primary);color:#fff;transform:translateY(-2px)}
.btn-sm{padding:.5rem 1.2rem;font-size:.88rem}
.btn-green{background:linear-gradient(135deg,#34a853,#1e7e34);color:#fff;box-shadow:0 4px 14px rgba(52,168,83,.3)}
.btn-green:hover{transform:translateY(-2px);box-shadow:0 8px 20px rgba(52,168,83,.4)}

.hero-visual{flex:1;display:flex;flex-direction:column;align-items:center;gap:1.2rem;position:relative;z-index:1}
.hero-cards{display:grid;grid-template-columns:1fr 1fr;gap:1rem;max-width:380px;width:100%}
.h-card{background:var(--card-bg);border-radius:var(--radius-sm);padding:1.2rem;border:1px solid var(--border);box-shadow:var(--shadow);text-align:center;transition:var(--transition)}
.h-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.h-card i{font-size:1.6rem;margin-bottom:.5rem;display:block}
.h-card span{font-size:.9rem;font-weight:600}
.h-card.c1 i{color:#1a73e8}.h-card.c2 i{color:#34a853}.h-card.c3 i{color:#e67e22}.h-card.c4 i{color:#9b59b6}

/* ── STATS ── */
.stats{display:flex;justify-content:center;flex-wrap:wrap;gap:0;background:var(--gradient);overflow:hidden}
.stat{text-align:center;color:#fff;padding:2.5rem 3rem;position:relative;flex:1;min-width:150px}
.stat::after{content:"";position:absolute;left:0;top:20%;height:60%;width:1px;background:rgba(255,255,255,.2)}
.stat:first-child::after{display:none}
.stat h2{font-size:2.8rem;font-weight:900;line-height:1}
.stat p{font-size:.9rem;opacity:.85;margin-top:.3rem}

/* ── SECTIONS ── */
.section{padding:5rem 4rem}
.section-header{text-align:center;margin-bottom:3rem}
.section-header h2{font-size:2rem;font-weight:800;margin-bottom:.6rem}
.section-header p{color:var(--text2);font-size:1rem;max-width:500px;margin:0 auto}
.section-header h2::after{content:"";display:block;width:56px;height:4px;background:var(--gradient);margin:.7rem auto 0;border-radius:2px}

/* ── CHAPTER CARDS ── */
.cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:1.6rem}
.card{background:var(--card-bg);border-radius:var(--radius);padding:1.8rem;box-shadow:var(--shadow);border:1px solid var(--border);transition:var(--transition);display:block;position:relative;overflow:hidden}
.card::before{content:"";position:absolute;top:0;right:0;width:100%;height:4px;background:var(--gradient);transform:scaleX(0);transition:var(--transition);transform-origin:right}
.card:hover::before{transform:scaleX(1)}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow-lg)}
.card-icon{width:54px;height:54px;border-radius:14px;display:flex;align-items:center;justify-content:center;margin-bottom:1rem}
.card-icon i{font-size:1.4rem;color:#fff}
.bg1{background:linear-gradient(135deg,#1a73e8,#0d47a1)}
.bg2{background:linear-gradient(135deg,#34a853,#1e7e34)}
.bg3{background:linear-gradient(135deg,#e67e22,#ca6f1e)}
.bg4{background:linear-gradient(135deg,#9b59b6,#7d3c98)}
.bg5{background:linear-gradient(135deg,#e74c3c,#c0392b)}
.bg6{background:linear-gradient(135deg,#1abc9c,#148f77)}
.bg7{background:linear-gradient(135deg,#f39c12,#d68910)}
.bg8{background:linear-gradient(135deg,#2980b9,#1a5276)}
.card h3{font-size:1.05rem;margin-bottom:.5rem;font-weight:700}
.card p{color:var(--text2);font-size:.88rem;margin-bottom:.8rem;line-height:1.6}
.badge{display:inline-block;padding:.22rem .7rem;border-radius:20px;font-size:.75rem;font-weight:700}
.badge-blue{background:#e8f0fe;color:#1a73e8}
.badge-green{background:#e8f5e9;color:#34a853}
.badge-orange{background:#fff3e0;color:#e67e22}
.badge-purple{background:#f3e5f5;color:#9b59b6}
body.dark .badge-blue{background:#1e3a5f;color:#64b5f6}
body.dark .badge-green{background:#1b3a27;color:#81c784}
body.dark .badge-orange{background:#3e2723;color:#ffb74d}
body.dark .badge-purple{background:#311b4e;color:#ce93d8}

/* ── WHY ── */
.why{background:var(--bg2)}
.why-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:2rem}
.why-item{text-align:center;padding:2rem 1.2rem;border-radius:var(--radius);border:1px solid var(--border);background:var(--bg);transition:var(--transition)}
.why-item:hover{border-color:var(--primary);box-shadow:var(--shadow)}
.why-item .icon-wrap{width:60px;height:60px;border-radius:50%;background:var(--primary-light);display:flex;align-items:center;justify-content:center;margin:0 auto 1rem}
.why-item .icon-wrap i{font-size:1.5rem;color:var(--primary)}
.why-item h4{font-size:1rem;margin-bottom:.5rem;font-weight:700}
.why-item p{color:var(--text2);font-size:.88rem}

/* ── PROGRESS SECTION ── */
.progress-section{background:var(--bg2)}
.progress-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:1.2rem}
.prog-item{background:var(--card-bg);border-radius:var(--radius-sm);padding:1.2rem;border:1px solid var(--border);box-shadow:var(--shadow)}
.prog-item .prog-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:.7rem}
.prog-item .prog-name{font-size:.9rem;font-weight:600}
.prog-item .prog-pct{font-size:.85rem;color:var(--primary);font-weight:700}
.prog-bar-track{height:6px;background:var(--border);border-radius:3px}
.prog-bar-fill{height:100%;border-radius:3px;background:var(--gradient);transition:width .6s ease}

/* ── PAGE HERO ── */
.page-hero{padding:3.5rem 4rem;background:var(--gradient);color:#fff;text-align:center;position:relative;overflow:hidden}
.page-hero::before{content:"";position:absolute;top:-50%;left:-10%;width:500px;height:500px;background:rgba(255,255,255,.04);border-radius:50%}
.page-hero h1{font-size:2.2rem;font-weight:800;margin-bottom:.7rem;position:relative}
.page-hero p{opacity:.9;font-size:1rem;position:relative;max-width:500px;margin:0 auto}

/* ── LESSONS ── */
.lessons-layout{display:grid;grid-template-columns:270px 1fr;gap:2rem;padding:2.5rem 3rem}
.sidebar{position:sticky;top:82px;height:fit-content}
.sidebar-nav{background:var(--card-bg);border-radius:var(--radius);padding:1.2rem;box-shadow:var(--shadow);border:1px solid var(--border)}
.sidebar-nav .s-title{font-size:.8rem;color:var(--text2);padding:.4rem .8rem;text-transform:uppercase;letter-spacing:1.5px;font-weight:700}
.sidebar-nav a{display:flex;align-items:center;gap:.7rem;padding:.65rem .8rem;border-radius:9px;font-size:.88rem;color:var(--text);transition:var(--transition);margin:.1rem 0}
.sidebar-nav a .ch-num{width:22px;height:22px;border-radius:50%;background:var(--border);display:flex;align-items:center;justify-content:center;font-size:.72rem;font-weight:800;flex-shrink:0;transition:var(--transition)}
.sidebar-nav a:hover,.sidebar-nav a.active{background:var(--primary-light);color:var(--primary)}
.sidebar-nav a:hover .ch-num,.sidebar-nav a.active .ch-num{background:var(--primary);color:#fff}
.sidebar-nav a.done{color:var(--accent2)}
.sidebar-nav a.done .ch-num{background:var(--accent2);color:#fff}
.lesson-content{display:flex;flex-direction:column;gap:2.5rem}

.lesson-box{background:var(--card-bg);border-radius:var(--radius);padding:2.5rem;box-shadow:var(--shadow);border:1px solid var(--border);transition:var(--transition)}
.lesson-box:hover{box-shadow:var(--shadow-lg)}
.lesson-box .box-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1.5rem;flex-wrap:gap}
.lesson-box h2{font-size:1.55rem;color:var(--primary);display:flex;align-items:center;gap:.8rem;font-weight:800}
.mark-done-btn{padding:.35rem .9rem;border-radius:8px;border:1.5px solid var(--accent2);color:var(--accent2);background:none;cursor:pointer;font-size:.82rem;font-weight:700;font-family:inherit;transition:var(--transition)}
.mark-done-btn.done{background:var(--accent2);color:#fff}
.mark-done-btn:hover{transform:scale(1.04)}
.lesson-box p{line-height:1.9;color:var(--text);margin-bottom:1rem}
.lesson-box h3{font-size:1.05rem;margin:1.5rem 0 .6rem;font-weight:700;padding-right:.8rem;border-right:3px solid var(--primary)}
.equation-box{background:linear-gradient(135deg,var(--primary-light),#dbeafe);border:2px solid var(--primary);border-radius:14px;padding:1.5rem;text-align:center;margin:1.5rem 0;font-size:1.3rem;font-weight:800;color:var(--primary);letter-spacing:.5px}
body.dark .equation-box{background:linear-gradient(135deg,#1e3a5f,#1a2a4a)}

.journal-table{width:100%;border-collapse:collapse;margin:1.5rem 0;font-size:.93rem;border-radius:10px;overflow:hidden;box-shadow:var(--shadow)}
.journal-table th{background:var(--gradient);color:#fff;padding:.85rem 1rem;text-align:center;font-weight:700}
.journal-table td{padding:.75rem 1rem;border:1px solid var(--border);text-align:center}
.journal-table tr:nth-child(even){background:var(--bg)}
.journal-table tr:hover{background:var(--primary-light)}
.debit{color:#1a73e8;font-weight:700}
.credit{color:#e74c3c;font-weight:700;padding-right:2rem}

.t-account{display:grid;grid-template-columns:1fr 1fr;border:2px solid var(--border);border-radius:12px;overflow:hidden;margin:1.2rem 0;box-shadow:var(--shadow)}
.t-account .t-header{grid-column:1/-1;background:var(--gradient);color:#fff;text-align:center;padding:.7rem;font-weight:800;font-size:.95rem}
.t-side{padding:1rem}.t-side h4{text-align:center;font-size:.82rem;color:var(--text2);border-bottom:1px solid var(--border);padding-bottom:.4rem;margin-bottom:.6rem;font-weight:700}
.t-right{border-right:2px solid var(--border)}
.t-side p{font-size:.9rem;padding:.2rem 0;color:var(--text)}

.info-box{background:linear-gradient(135deg,#fffde7,#fff8e1);border-right:4px solid var(--accent);padding:1rem 1.2rem;border-radius:10px;margin:1rem 0;color:#5a4a00;font-size:.93rem}
body.dark .info-box{background:linear-gradient(135deg,#2a2008,#1e1800);color:#e0c97f}
.success-box{background:linear-gradient(135deg,#e8f5e9,#f1f8e9);border-right:4px solid #34a853;padding:1rem 1.2rem;border-radius:10px;margin:1rem 0;color:#1b5e20;font-size:.93rem}
body.dark .success-box{background:linear-gradient(135deg,#1b3a27,#152d1e);color:#a5d6a7}
.danger-box{background:linear-gradient(135deg,#fce4ec,#fce4ec);border-right:4px solid #e74c3c;padding:1rem 1.2rem;border-radius:10px;margin:1rem 0;color:#7f0000;font-size:.93rem}
body.dark .danger-box{background:linear-gradient(135deg,#3e1218,#2d0d11);color:#ef9a9a}

.steps{counter-reset:step;display:flex;flex-direction:column;gap:.8rem;margin:1rem 0}
.step-item{display:flex;align-items:flex-start;gap:1rem;padding:1rem;background:var(--bg);border-radius:10px;border:1px solid var(--border)}
.step-item::before{counter-increment:step;content:counter(step);min-width:32px;height:32px;border-radius:50%;background:var(--gradient);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:.9rem;flex-shrink:0}
.step-item p{margin:0;font-size:.93rem}

/* ── INVENTORY TABLE ── */
.inv-table{width:100%;border-collapse:collapse;margin:1.2rem 0;font-size:.9rem;border-radius:10px;overflow:hidden;box-shadow:var(--shadow)}
.inv-table th{background:linear-gradient(135deg,#e67e22,#ca6f1e);color:#fff;padding:.7rem .9rem;text-align:center}
.inv-table td{padding:.6rem .9rem;border:1px solid var(--border);text-align:center}
.inv-table tr:nth-child(even){background:var(--bg)}
.inv-table .total-row{background:var(--primary-light)!important;font-weight:800;color:var(--primary)}

/* ── QUIZ ── */
.quiz-container{max-width:820px;margin:2.5rem auto;padding:0 2rem}
.quiz-header{text-align:center;margin-bottom:1.5rem}
.quiz-header h1{font-size:2rem;color:var(--primary);font-weight:800}
.quiz-header p{color:var(--text2)}
.quiz-filters{display:flex;justify-content:center;gap:.7rem;flex-wrap:wrap;margin-bottom:1.5rem}
.quiz-filter-btn{padding:.45rem 1.1rem;border-radius:20px;border:1.5px solid var(--border);background:var(--bg2);color:var(--text2);font-size:.85rem;cursor:pointer;font-family:inherit;transition:var(--transition)}
.quiz-filter-btn:hover,.quiz-filter-btn.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.quiz-card{background:var(--card-bg);border-radius:var(--radius);padding:2.5rem;box-shadow:var(--shadow);border:1px solid var(--border)}
.question-counter{font-size:.88rem;color:var(--text2);margin-bottom:.4rem;font-weight:600}
.progress-bar{height:7px;background:var(--border);border-radius:4px;margin-bottom:1.8rem;overflow:hidden}
.progress-fill{height:100%;background:var(--gradient);border-radius:4px;transition:width .4s ease}
.question-text{font-size:1.15rem;font-weight:700;margin-bottom:1.5rem;line-height:1.65}
.options{display:flex;flex-direction:column;gap:.75rem;margin-bottom:1.5rem}
.option-btn{padding:.9rem 1.2rem;border:2px solid var(--border);border-radius:11px;background:var(--bg);color:var(--text);font-size:.97rem;cursor:pointer;text-align:right;font-family:inherit;transition:var(--transition);font-weight:500}
.option-btn:hover:not(:disabled){border-color:var(--primary);background:var(--primary-light);transform:translateX(-3px)}
.option-btn:disabled{cursor:default}
.option-btn.correct{background:#e8f5e9;border-color:#34a853;color:#1b5e20}
.option-btn.wrong{background:#fce4ec;border-color:#e74c3c;color:#b71c1c}
.feedback{padding:1rem 1.2rem;border-radius:10px;margin-bottom:1.2rem;font-weight:600;font-size:.93rem;display:none}
.feedback.show{display:block}
.feedback.correct{background:#e8f5e9;color:#1b5e20;border:1px solid #34a853}
.feedback.wrong{background:#fce4ec;color:#b71c1c;border:1px solid #e74c3c}
.quiz-nav{display:flex;justify-content:space-between;align-items:center}
.score-screen{text-align:center;padding:3rem 2rem}
.score-circle{width:150px;height:150px;border-radius:50%;border:8px solid var(--primary);margin:0 auto 1.5rem;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--primary-light)}
.score-circle span{font-size:2.8rem;font-weight:900;color:var(--primary);line-height:1}
.score-circle small{font-size:.78rem;color:var(--text2)}
.score-screen h2{font-size:1.6rem;font-weight:800;margin-bottom:.8rem}
.score-screen p{color:var(--text2);margin-bottom:1.5rem}
.score-breakdown{display:flex;justify-content:center;gap:2rem;margin-bottom:2rem;flex-wrap:wrap}
.score-item{text-align:center;padding:1rem 1.5rem;border-radius:12px;border:1px solid var(--border)}
.score-item .si-num{font-size:1.8rem;font-weight:900}
.score-item .si-label{font-size:.82rem;color:var(--text2)}
.score-item.si-correct .si-num{color:#34a853}
.score-item.si-wrong .si-num{color:#e74c3c}
.score-item.si-skip .si-num{color:var(--accent)}

/* ── GLOSSARY ── */
.glossary-container{max-width:1000px;margin:0 auto;padding:2.5rem 2rem}
.search-bar{position:relative;margin-bottom:2rem}
.search-bar input{width:100%;padding:.9rem 1.2rem .9rem 3rem;border:2px solid var(--border);border-radius:12px;font-size:1rem;background:var(--bg2);color:var(--text);font-family:inherit;transition:var(--transition)}
.search-bar input:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px rgba(26,115,232,.15)}
.search-bar .s-icon{position:absolute;left:1rem;top:50%;transform:translateY(-50%);color:var(--text2)}
.alpha-filter{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1.5rem}
.alpha-btn{padding:.3rem .7rem;border-radius:7px;border:1.5px solid var(--border);background:var(--bg2);color:var(--text2);font-size:.83rem;cursor:pointer;font-family:inherit;transition:var(--transition)}
.alpha-btn:hover,.alpha-btn.active{background:var(--primary);color:#fff;border-color:var(--primary)}
.glossary-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(270px,1fr));gap:1.2rem}
.glossary-item{background:var(--card-bg);border-radius:12px;padding:1.2rem 1.3rem;border:1px solid var(--border);box-shadow:var(--shadow);transition:var(--transition)}
.glossary-item:hover{border-color:var(--primary);transform:translateY(-2px)}
.glossary-item .term-ar{font-size:1.05rem;font-weight:800;color:var(--primary);margin-bottom:.2rem}
.glossary-item .term-en{font-size:.82rem;color:var(--text2);font-style:italic;margin-bottom:.6rem}
.glossary-item .term-def{font-size:.88rem;color:var(--text);line-height:1.65}
.no-results{text-align:center;padding:3rem;color:var(--text2)}

/* ── FORMULAS ── */
.formulas-container{max-width:1000px;margin:0 auto;padding:2.5rem 2rem}
.formula-category{margin-bottom:3rem}
.formula-category h2{font-size:1.4rem;font-weight:800;color:var(--primary);margin-bottom:1.2rem;display:flex;align-items:center;gap:.7rem}
.formula-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(420px,1fr));gap:1.3rem}
.formula-card{background:var(--card-bg);border-radius:var(--radius);padding:1.8rem;box-shadow:var(--shadow);border:1px solid var(--border);transition:var(--transition)}
.formula-card:hover{border-color:var(--primary);transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.formula-card h3{color:var(--text);margin-bottom:.8rem;font-size:1rem;font-weight:700;display:flex;align-items:center;gap:.5rem}
.formula-box{background:var(--primary-light);border:2px dashed var(--primary);border-radius:10px;padding:1.1rem;text-align:center;font-size:1.05rem;font-weight:800;color:var(--primary);margin:.8rem 0;letter-spacing:.3px}
body.dark .formula-box{background:#1e3a5f}
.formula-card p{color:var(--text2);font-size:.88rem;line-height:1.7}

/* ── EXERCISES ── */
.exercises-container{max-width:900px;margin:0 auto;padding:2.5rem 2rem}
.exercise-card{background:var(--card-bg);border-radius:var(--radius);padding:2rem;box-shadow:var(--shadow);border:1px solid var(--border);margin-bottom:1.8rem;transition:var(--transition)}
.exercise-card:hover{box-shadow:var(--shadow-lg)}
.ex-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.2rem;flex-wrap:wrap;gap:.5rem}
.ex-title{font-size:1.15rem;font-weight:800;color:var(--primary)}
.ex-badge{padding:.3rem .9rem;border-radius:20px;font-size:.78rem;font-weight:700}
.ex-easy{background:#e8f5e9;color:#34a853}
.ex-medium{background:#fff3e0;color:#e67e22}
.ex-hard{background:#fce4ec;color:#e74c3c}
.ex-question{background:var(--bg);padding:1.2rem;border-radius:10px;margin-bottom:1.2rem;font-size:.95rem;line-height:1.75;border-right:3px solid var(--primary)}
.ex-solution{display:none;background:linear-gradient(135deg,#e8f5e9,#f1f8e9);padding:1.2rem;border-radius:10px;border:1px solid #34a853;margin-top:1rem}
body.dark .ex-solution{background:linear-gradient(135deg,#1b3a27,#152d1e);border-color:#34a853}
.ex-solution.show{display:block}
.ex-solution h4{color:#34a853;margin-bottom:.8rem;font-size:.95rem}
.ex-solution p,.ex-solution table{font-size:.9rem}
.toggle-solution{margin-top:.5rem}

/* ── CALCULATOR ── */
.calc-container{max-width:900px;margin:2.5rem auto;padding:0 2rem}
.calc-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(380px,1fr));gap:1.5rem}
.calc-card{background:var(--card-bg);border-radius:var(--radius);padding:2rem;box-shadow:var(--shadow);border:1px solid var(--border)}
.calc-card h3{color:var(--primary);font-size:1rem;font-weight:800;margin-bottom:1.2rem;display:flex;align-items:center;gap:.5rem}
.calc-inputs{display:flex;flex-direction:column;gap:.8rem;margin-bottom:1rem}
.calc-inputs label{font-size:.85rem;color:var(--text2);font-weight:600;margin-bottom:.2rem;display:block}
.calc-inputs input{width:100%;padding:.7rem 1rem;border:1.5px solid var(--border);border-radius:9px;font-size:.95rem;background:var(--bg);color:var(--text);font-family:inherit;transition:var(--transition)}
.calc-inputs input:focus{outline:none;border-color:var(--primary);background:var(--bg2)}
.calc-result{background:var(--primary-light);border-radius:10px;padding:1rem;text-align:center;margin-top:1rem;font-size:1.2rem;font-weight:800;color:var(--primary);min-height:52px;display:flex;align-items:center;justify-content:center}
body.dark .calc-result{background:#1e3a5f}

/* ── CHEAT SHEET ── */
.cheat-container{max-width:1100px;margin:0 auto;padding:2.5rem 2rem}
.cheat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:1.5rem}
.cheat-card{background:var(--card-bg);border-radius:var(--radius);padding:1.8rem;box-shadow:var(--shadow);border:1px solid var(--border)}
.cheat-card h3{font-size:1rem;font-weight:800;margin-bottom:1rem;padding-bottom:.6rem;border-bottom:2px solid var(--primary);color:var(--primary);display:flex;align-items:center;gap:.5rem}
.cheat-card table{width:100%;font-size:.85rem;border-collapse:collapse}
.cheat-card table td{padding:.45rem .6rem;border-bottom:1px solid var(--border);vertical-align:top}
.cheat-card table td:first-child{font-weight:700;color:var(--text);width:45%}
.cheat-card table td:last-child{color:var(--text2)}
.print-btn{position:fixed;bottom:2rem;left:2rem;z-index:100}

/* ── FOOTER ── */
.footer{padding:2.5rem 3rem;background:var(--bg2);border-top:1px solid var(--border);text-align:center}
.footer-content{max-width:700px;margin:0 auto}
.footer p{color:var(--text2);font-size:.9rem;margin:.3rem 0}
.footer-links{display:flex;justify-content:center;gap:1.5rem;margin-top:.8rem;flex-wrap:wrap}
.footer-links a{color:var(--text2);font-size:.85rem;transition:var(--transition)}
.footer-links a:hover{color:var(--primary)}

/* ── NOTIFICATION ── */
.toast{position:fixed;bottom:2rem;right:2rem;background:#1e2235;color:#fff;padding:.8rem 1.4rem;border-radius:10px;font-size:.9rem;font-weight:600;z-index:9999;transform:translateY(100px);opacity:0;transition:all .4s ease;border-right:4px solid var(--accent2)}
.toast.show{transform:translateY(0);opacity:1}

/* ── RESPONSIVE ── */
@media(max-width:1024px){.lessons-layout{grid-template-columns:1fr;padding:1.5rem}.sidebar{display:none}.section{padding:3rem 2rem}.hero{padding:3.5rem 2rem}}
@media(max-width:768px){.hero{flex-direction:column;text-align:center}.hero-btns{justify-content:center}.hero-visual{display:none}.hero-content h1{font-size:2rem}.nav-links{display:none!important}.nav-toggle{display:block}.stats .stat{padding:2rem 1.5rem}.section{padding:2.5rem 1.5rem}.lessons-layout{padding:1rem}.page-hero{padding:2.5rem 1.5rem}.nav-links.open{display:flex!important;flex-direction:column;align-items:stretch;width:100%;background:var(--card-bg);border-radius:var(--radius);padding:.8rem;margin-top:.3rem;box-shadow:var(--shadow);border:1px solid var(--border);gap:.25rem}.nav-links.open a{padding:.65rem 1rem;font-size:.9rem}.formula-grid{grid-template-columns:1fr}.calc-grid{grid-template-columns:1fr}}
@media print{.navbar,.footer,.mark-done-btn,.print-btn{display:none}.cheat-card{break-inside:avoid}}
/* ═══════════════════════════════════════════════
   إضافات 2026 — نظيفة بدون تكرارات
═══════════════════════════════════════════════ */

/* ── nav-toggle hover ── */
.nav-toggle:hover{background:var(--primary-light);color:var(--primary)}

/* ── badge مستوى دراسات الحالة والتمارين ── */
.case-tag,.ex-badge{display:inline-block;padding:.2rem .75rem;border-radius:20px;font-size:.76rem;font-weight:700}
.tag-green,.ex-easy{background:#e8f5e9;color:#1b5e20}
.tag-yellow,.ex-medium{background:#fff8e1;color:#e65100}
.tag-red,.ex-hard{background:#fce4ec;color:#b71c1c}
.tag-blue{background:#e8f0fe;color:#1a73e8}
body.dark .tag-green,body.dark .ex-easy{background:#1b3a27;color:#81c784}
body.dark .tag-yellow,body.dark .ex-medium{background:#3e2723;color:#ffb74d}
body.dark .tag-red,body.dark .ex-hard{background:#3e0f0f;color:#ef9a9a}
body.dark .tag-blue{background:#1e3a5f;color:#64b5f6}

/* ── case-card بشكل صحيح ── */
.case-card{background:var(--card-bg);border-radius:var(--radius);padding:2rem;box-shadow:var(--shadow);border:1px solid var(--border);margin-bottom:1.8rem;transition:var(--transition)}
.case-card:hover{box-shadow:var(--shadow-lg);border-color:var(--primary)}
.case-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:1.2rem;flex-wrap:wrap;gap:.6rem}
.case-header h3{font-size:1.1rem;font-weight:800;color:var(--primary);display:flex;align-items:center;gap:.5rem}
.case-body p{line-height:1.85;font-size:.93rem;color:var(--text);margin-bottom:.7rem}

/* ── تحسينات بصرية عامة ── */
body{-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}
h1,h2,h3,h4{line-height:1.3}
img,iframe{max-width:100%}

/* ── progress-bar-wrap (للوحة التقدم) ── */
.progress-bar-wrap{background:var(--border);border-radius:10px;overflow:hidden;height:8px}
.progress-bar-fill{height:100%;background:var(--gradient);border-radius:10px;transition:width .6s ease}

/* ── search-box في الرئيسية ── */
.search-box input{padding:.75rem 1.2rem;border-radius:12px;border:2px solid var(--border);background:var(--bg2);color:var(--text);font-size:.95rem;font-family:inherit;width:100%;max-width:480px;outline:none;transition:var(--transition)}
.search-box input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(26,115,232,.15)}
.search-results{position:absolute;top:calc(100% + .5rem);right:0;left:0;background:var(--bg2);border:1px solid var(--border);border-radius:12px;box-shadow:var(--shadow-lg);overflow:hidden;display:none;z-index:200}
.search-results.show{display:block}
.search-item{display:flex;justify-content:space-between;align-items:center;padding:.7rem 1.1rem;font-size:.9rem;color:var(--text);border-bottom:1px solid var(--border);transition:var(--transition)}
.search-item:last-child{border-bottom:none}
.search-item:hover{background:var(--primary-light);color:var(--primary)}
.search-item span{font-size:.75rem;background:var(--primary-light);color:var(--primary);padding:.18rem .6rem;border-radius:8px;font-weight:700}

/* ── sections الرئيسية ── */
.section-title{font-size:1.7rem;font-weight:800;text-align:center;margin-bottom:2rem;position:relative;color:var(--text)}
.section-title::after{content:"";display:block;width:50px;height:4px;background:var(--gradient);border-radius:2px;margin:.6rem auto 0}
.why-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:1.5rem}
.why-item{text-align:center;padding:1.8rem 1.2rem;border-radius:var(--radius);border:1px solid var(--border);background:var(--card-bg);transition:var(--transition)}
.why-item:hover{border-color:var(--primary);box-shadow:var(--shadow);transform:translateY(-3px)}
.why-item i{font-size:2rem;color:var(--primary);display:block;margin-bottom:.8rem}
.why-item h4{font-size:.98rem;margin-bottom:.4rem;font-weight:700}
.why-item p{color:var(--text2);font-size:.85rem;line-height:1.6}

/* ── إصلاح تشوه padding في الـ sections ── */
@media(max-width:600px){
  .section{padding:2rem 1rem}
  .quiz-container,.exercises-container,.glossary-container,.formulas-container{padding:1.5rem 1rem}
  .lesson-box{padding:1.5rem}
  .hero-content h1{font-size:1.7rem}
  .cards-grid{grid-template-columns:1fr}
  .formula-grid,.calc-grid{grid-template-columns:1fr}
  .fm-grid{grid-template-columns:1fr!important}
  .gl-grid{grid-template-columns:1fr!important}
}

/* ═══ إصلاح عام — جداول على الجوال ═══ */
.table-scroll{overflow-x:auto;-webkit-overflow-scrolling:touch;border-radius:10px}
.table-scroll::-webkit-scrollbar{height:5px}
.table-scroll::-webkit-scrollbar-thumb{background:var(--primary);border-radius:3px}
.journal-table,.inv-table,.cheat-card table,.dep-table{min-width:400px}
table{border-collapse:collapse;width:100%}
th,td{white-space:nowrap}

/* ─── إصلاح: result-row على الجوال ─── */
@media(max-width:480px){
  .result-row{flex-direction:column;align-items:flex-start;gap:.2rem}
  .result-row .val{font-size:.95rem}
  .ratio-grid{grid-template-columns:1fr 1fr}
  .dep-table th,.dep-table td{font-size:.78rem;padding:.5rem .6rem}
  .calc-tabs{gap:.3rem}
  .calc-tab{font-size:.78rem;padding:.45rem .8rem}
}